Drugs only screw up your life, if you take drugs while you should be working, or stay wasted when you should be ready to start work, or if you want more drugs than you can comfortably afford. Responsible drug addicts do not have to sell and buy back their TV twice a month.
Most drug users can use the worst drugs responsibly and in moderation, while keeping a job, and paying their mortgage, and raising children.
On a long enough timeline Cocaine is going to fuck you up and kill you, but the same is true about alcohol and cigarettes.
Think about the size of the drug economy, trillions of dollars a year change hands, the Popo tells us, but if everyone that took drugs died on the streets a week later, drugs would be an unsustainable industry and the human race would have died out in the 1970s.
Having an addictive personality leading to serious drug addiction is a little bit nature and a little bit nurture but it's mostly about being an asshole, and it's only a small percentage of the actual people consuming all the drugs who other wise lead normal uneventful lives, who fit the addicted stereotype of a drug addict. The consequences of abusing drugs and not maintaining the infrastructure of your life is totally foreseeable and only an idiot (asshole) would spend his rent on smack, and his electricity bill on gambling and get wasted at work so bad that peeing in the water cooler seems like a good idea, that he's fired.
The problem is that addicts who blow up, are so loud about it, that these punks give drugs a bad name, and makes it harder for all the brave and privileged Americans out there who can handle their Meth and a 9 to 5. Actually if you have enough meth you can handle two 9 to 5s. Regardless you've been fed halftruths about the %1 of drug users and been lead to believe that these stories are documentaries about the %99.
Don't take drugs.
Stay in school.